I was looking around for info. on this particular Getter Robo but I couldn't find any, so I asked around the anime toy forums to help me out. Do you know?
I didn't get a straight answer, only that the purple color indicates that this Getter Robo papercraft is based on the Getter Robo Training Model/Machine series. Never heard of that one as well, so if you do, just mention it below.
Hat tip to reader Kristoff for the link and files.